Drawbench



Aug. 9, 1932. R. D. PALMER ET AL 39870419 DRAWBENCH Filed May 16, 1929 l0 Sheets-Sheet l if E y INVENTORS @kwas P QM WW, www

Aug. 9, 1932. R. D. PALMER ET AL 1,870,419

DRAWBENCH Filed May 16, 1929 10 Shee'cs--S11eerl 2 NHHHHHJLL. ---lhlldulnuvmwn R. D. PALMER ET Al. 1,870,419

DRWBENCH -Filed May 16, 1929 10 Sheets-Sheet 5 Aug. 9, i932.,

weTNEsSEs Aug 9, 1932-l R. D. PALMER ET AL 1,870,419

DRAWBENCH Filed May 16, 1929 10 Sheets-Sheet 4 nl 46 if@ 4 A// /u//fv Aug. g, w32 R D. PALMER ET AL 5987094@ DRAWBENCH Filed May 16, 1929 lO Sheets-'Sheet 5 Aug. 9, 1932. R. D. PALMER ET AL DRAWBENCH Filed May 16, 1929 10 SheecS-Sheet 6 .wm www WN wwnesses lgl 9, ggg. :Q PALMER ET AL LF@ DRWBENCH Filed May 16 1929 10 Shees-Sheeh 7 WUTNESS INVENTORS @m 55- @Mr ML PALMERv ET M LS'YAQ DRWBENCH lO Sheets-Sheet 8 INVENTORS SWK. @MMA l Aug., 9? E932.,

Filed May 16, 1929 All@ 9, 1932t R. D. PALMER ET'AL l,870,41

DRAwBENCH Fild May 16, 1929 10 Sheets-Sheet 9' Aug., Q, w32. R. D. PALMER ET AL DRAWBENCH Filed May 16, 1929 10 Sheets-Sheet 10 Patented Aue. 99 i932 ROYJ). lIE'.ALT/J2EE., 0F OAKMONT, AND ROLAND L. JEFFERS, OF PARNSSUS, PENNSYJ- y VANIA, ASSIGNORS TO ALUMNUM COMPANY OF AMERICA, OF PITTSBURGH, PENN- SYLVANIA, A CORPORATION OF PENNSYLVANIA DRAWBENCI- Application led May 16,

rllhis invention pertains to apparatus for drawing metals, and relates especially to apparatus for drawing tubes by the use of a die and bulb.

It `is an object of the invention to produce a drawing apparatus which will be especially lrapid in its operation, as well as particularly convenient both for the feeding in of As an example of one form which the invention may take, a tube drawing apparatus constructed in accordance therewith is described in the following specification and shown in the accompanying drawings; but it is to be understood that the invention may be embodied in other forms and that changes may be made in the form described and shown without exceeding the scope thereof as de- -tined in the appended claims.

In the drawings: A Figs. 1a, 1?) and 1c constitute together a side elevation of a tube drawing apparatus constructed in accordance with the invention;

Fig. 2 [Sheet 1l is a section taken through the bulb-rod manipulating device, the section belngv on the line 2 2 of Fig. la, looking in the direction of the arrows;

Fig. 3 [Sheet 2] is a section taken through the feed table, on the line 3 3 of Fig. 1b;

Fig. 4 is a section through the draw bench, the section being taken on the line 4- 4 of Fig. 1c and showing the feed rack and de# livery trough as well as the channel-iron supports in which the draw chains run and upon which the draw heads travel;

Fig. 5 is an end view of the draw bench, as

1929. Serial No. 363,661.

seen from the line 5 5 of Fig. 1c, showing the face of the die holder;

Figs. 6 and 7 are aside elevation and a plan, respectively, of one of the draw heads, showing the draw chain engaging hook mounted thereon, and the work engaging tongs carried thereby; v

Figs. 8, 9, 10 and 11 are sections taken on the lines 8 8, 9 9, 10-10, and 11 11, respectively, of Fig. 6; Y

Figs. 12 and 13 are a side elevation and a central section respectively, of one of the fluid operated devices for actuating the chain engaging hooks on the draw heads, to cause the 'latter to interlock with a chain and thereby start the drawing operation;

Figs. 14 and 15 are a side elevation and a sectional plan, respectively, of one of the lplunger devices for cushioning the return movement of the draw heads;

Figs. 16 and 17 are a plan and a sectional elevation, respectively, showing one of the fluid operated devices for manipulating the bulb rods to force the bulbs into proper cooperative position with respect to the dies after the drawing operation has started;

Fig.718 is a-section on the line 18 18 of Fig. l

Figs. 19 and 20 are a side elevation and a. plan, respectively, of mechanism for controlling the operation of the valves for the bulb rod manipulating devices so as to enable the bulbs to be forced into cooperative position with respect to the dies after the proper' period has elapsed following the starting of the drawing operation, said valve controlling mechanism being operatively associated with the plunger devices for cushioning the return movements of the draw heads; and

Figs. 21 and 22 are sections on the lines 21-21 and 22-22, respectively, of Fig. 19.

Briefly and in general, the particular apparatus which has been chosen for ldescription and illustration as an embodiment of the invention comprises a draw bench which includes channel-iron supports disposed side by side and from which a pair of draw heads are suspended so as to be capable of traveling lengthwise thereof. Associated with these supports are a pair of endless chains, one foreach draw head, with which chains the draw heads can be interlocked, by means of hooks carried thereby, when the drawing operation is to be started. Manually coiitrolled power-operated means is provided for effecting the interlocking of each draw head with its chain; so that the two drawheads can be operated independently of each other. The disconnection of the draw heads from the chains, however, is automatic, and is occasioned by the jar occurring when the tube leaves the die upon the completion of the drawing operation.

The draw bench alsosincludes a rack disposed above the draw chains and upon which the supply of blanks is placed in a position enabling a blank to be conveniently taken by the operator for'being inserted into the tongs of a draw head. In addition the draw bench is provided with a delivery trough into which the drawn vtubes fall, from inclined skids, when they are released from the suspended draw heads upon the drawing operation being completed.

The apparatus further comprises a mechanisin for automatically returning the draw heads when they have become released from the draw chains upon the completion of the drawing operation. This mechanism includes a pair of drums frictionally mounted upon a continuously rotating shaft. Cables wound on these drums are secured to the draw heads, with the result that, during the I movement of a headto draw a tube, its drum rotates, against the friction, in the opposite direction to that of the rotation of the drum shaft. When, howeventhe drawing operation is completed and the carriage is released from its chain, the cable drum, by reason of its frictional mounting on its shaft, winds up the cable and returns the draw head.

The apparatus further comprises a means for cushioning the return movements of the i draw-heads, which cushioning means consists of a pair of dash-pot plungers, one for each draw head. Each plunger has means for impositively connecting it with its draw -head, so that the plunger is pulled out by the draw head during the first part rof the drawing movement of the latter and thereby brought to a position where it will be engaged by the draw head at the end of the return movement lof the latter, thus to exercise its cushioning function.

In starting the operation ofv the'apparatus a tube is threaded by the operator on to a b ulb rod, and its end, which has beenpreliminiarily swaged down, is passed through one of the dies and inserted into the jaws Of eration of the valves for which is controlled by mechanism actuated from stems extending from the cushioning plungers above referred to. This mechanism is adjustable so that the bulbs may be forced home with respect to their dies at various periods after the starting of the drawing operation, depending upon the requirements of each particular case.

Referring now to the drawings, in which like reference characters refer to like parts throughout the several figures thereof, the draw bench comprises an end stand 30 for supporting the die holder 30a in which are carried at a, the dies through which the tubes are to be drawn (Fig. 5). The bench further comprises a plurality of support frame 31, the end stand and support frames being connected together so as to form a solid structure by a pair of longitudinal I-beams 32, 33 placed at the rear thereof,'and an I-beam 34 and an angle iron 35 placed at the front (Figs. 1c, 4 and 5) The support frames 31 are provided with overhanging brackets 36 to which are secured a pair of channel iron supports 37 disposed side by side and upon each of which one of the draw heads is adapted to travel, these supports being enlarged at their ends 37a for connection with the end stand 30. The supports 37 are of H-shape in cross section so as to provide ways in which endlessI draw chains 38 can run. Each of these chains runs over a sprocket 39 disposed close to the stand 30 and, at the other end of the machine, over a driving sprocket, not necessary to be shown. Thus the lower parts or lower reaches the bench uprights 41 are provided. Between the uprights 41 and the I-beam 34 at the front of the bench, plates are secured so as to form trough sections l42, which sections form a trough for receiving the drawn\tubes as they are releasedl from the suspended draw-heads and roll down the skids 40.

Secured to the rear I-beams 32 and 33l are a I plurality of posts 43, to the top ends of which are secured rack bars 44 which are inclined slightly downwardly and forwardly. The

rear ends of `these rack bars are braced by diagonal struts 45, and are provided with @11d members 46. The front ends of the rack bars are attached to vertical members 47 secured to the angle iron 85. The manner of attachment of the rack bars 44 to the posts 43 and the vertical members 47 is such that l each rack bar occupies a level slightly higher thanthe preceding one from the front toy will be hereinafter described.

projects forwardly from the hub 57 of the.

The draw head which travels onthe support 37 shown at the left of Fig. 4 is illustrated in Figs. 6 to 11 inclusive. This draw head comprises a rear member 49 and a front member 50 slidably associated therewith by means of a slotted connection. The4 rear member includes a trough shaped portion 51 (Figs. 6 8) having lugs 52 extending upwardly from the sides thereof and carrying wheels 58 which run upon iianges 54 forming'part of the H-shaped supports 37. A pin 54a is secured in the portion 51 and has pivoted thereon the hub 55 of the chain engaging hook 56. The pin 54a extends outwardly to one side of the portion 51 and has pivoted thereon the hub 57 of a hook actuating lever 58, the lat- Ater being provided at its end with a roll 59 for engagement by. an actuating member as An arm 59a hook actuating lever 58 and is connectedl to the hook 56 by means of a pin 60 passing I through them both. It Willbe observed that this construction has. the result that the pulling strain exercised upon the hook 56, which is very considerable, is borne-by the pin 54a on each side of the bearing of the latter. The'` hook actuating lever 58 is weighted in such .'a manner as to be slightly overbalancedby thehook 56;v so that, unless the hook is engaged with its chain, it will drop into the "position shown'in 6, in which it rests upon the floor ofthe trough shaped portion 5.1 of the rear member49 of the draw head.

`The rear member 49 isformed with a shelf 61 extending longitudinally therefrom (Figs. 6, 7 and 10) which is .formed with. a longitudial slot 61a for receiving a shank 62 whichr extends rearwardly from the .front member 50 of the draw head. Pins 63 mounted in the shelf 61 engage in an elongated slot 64. formed in the shank 62,7thereby permitting a slight relative longitudinal movement between the front and rear members of the draw head. The front member 50, like the rear member 49. is formed with upwardly extending lugs 65 carrying wheels 66 which travel yon the flanges 54 of the supports 87.

The draw head carries a pair of tongs which include a pair of outside avv-levers 67 (Figs.

6, 7 and 11) and an inside jaw-lever 68 embraced between the outside levers, the whole being mounted upon a pivot pin 69 carried bythe front member 50 of the draw head. Opposed hardened and serratedjaws 70 and 71 are secured to the outside jaw-levers 67 and the inside jaw-lever 68, respectively. A pair of outside links 72 (Fig. 10) are pivotally connected with the inner jaw lever 68 by means of a pin 78; and these outsidelinks embrace between them at their other ends, an inside link 74 which is pivotally connected to the outside aw levers 67, between the latter, by means of a pin 75. The ends of the links 72 and 74 opposite to those which are pivoted to the jaw levers are pivoted upon a pin 76 which is carried by the rear member 49 of the draw head.

From the foregoing it will be seen tha-t when a drag is vexerted upon the rear member 49 of the draw head, the front member 50 be- .ing retarded against-movement (by means to be described-below), the tendency will be to straighten the tongs so that the jaws 70 and 71 approach each other and seize firmly anything which is between them. yOn the other hand, when, during the movement of the draw head, theend of the drawn tube 'finally leaves the die, it does so with a pronounced jerk in the direction of the movement of the draw head. This jerk, communicated to the front member 50 of the drawN head, causes the latter to move towards the rear member 49, the slotted connection permitting this. This movement of the front member 50 causes the jaws '70, 71 of the tongs to open,` permitting the tube to fall therefrom. lt will thus be seen that the/tongs close automatically upon the drawing movement being started and open automatically upon the drawn tube jerking free ofthe die.

In order to start the movement of the draw heads a pair of power'operated devices are provided, one for each draw 'he-ad. Each of these devices comprises a Huid pressure cylinder 77 mounted .in a socket 78 extending outwardly from the enlarged end 37a of. one of the supports 37. A plunger 78a, of relatively large diameter, is mounted in the cylinder 77 and has secured to the end thereof an abutment member 79 of U-shape, the legs 80 of the abutment member being guided in ears 81 extending laterally from the cylinder 77. The cylinder 77 is provided with an inlet 82 and with a second inlet 83, both of which inlets are 'connected with a source of supply of fluid under pressure. The inlet 83 isfin constant communication with such source of supply, but the inlet 82 can be cut off therefrom by means of a suitable valve. lVhen, by means of the valve, which is under control of the operator, pressure fluid is admitted to the inlet 82, the plunger 7 8a is depressed, by reason of the greater effective area above than below the piston. Thereby the abutment member 79 engages the roll 59 of the hook actuating lever 58 of the draw head and depresses the same, thus forcing the 'hook 56 upward to engage one of the cross links of the lower reach of the chain 38.

When the pressure fluid is cut off from the inlet 82, and the latter opened to the atmosphere, the pressure on the under side of the piston, communicated through the inlet 83, will cause the return upward of the plunger, ready for another downward operation when it is required again to start the movement of a draw head.

It will be seen from the above that when a tube, with its end swaged down and passed through the die, has been' inserted into the tongs of a draw head, and the corresponding operating mechanism actuated by the operator manipulating a valve to admit pressure iuid through the inlet 82 to the `air' cylinder 77, the hook 56 of the draw head will be forced upward and will engage one of the cross links vof the adjacent chain 38.

. Thereupon the draw head will start to move along the flanges 54y of the support 37 on which it travels, the first effect of such movement,` owing to theretarding of the front member 50 of the draw head, by means to be described below, being to'close the jaws 70 and 71 upon the tube end, whereafter the tube will be drawn through the die. When the end of the drawn tube emerges from the die, the tube will jerk forward forcibly, with the result that not only are the tongs opened, as described above, but the whole drawhead is jerked forward so as to free the hook 56 from the link with which it has been engaging, whereupon the hook being heavier than its actuating lever 58, will fall down out of engagement with the chain. The drawn tube,y released from the tongs, will fall onto the standards 4() and roll into the trough constituted by the trough sections 42, whence the tubes can be conveniently removed when a suitable number have accumulated.

In order to return each draw head to its starting position immediately upon the drawing operation being completed and its hook thereby being released from the chain, a cable 84.- (Figs. 1b, 3 and 5) is secured to the rear member 49 of-.each draw head -in any suitable manner, as, for instance, by securing the cable to a pin 85 extending laterally from such member (Figs. 7 and 9). `The cables 84 are wound upon drums 85a driven through suitable reduction gearing 86 from an electric motor 87. The drums 85a are mounted frictionally with respect to their shaft, so that they will normally tend to rotate in 'a direction to wind up the cables 84 on the drums. When either draw-head is connected with its adjacent draw-chain it overcomes the friction between the cable drum and its shaft and thus unwinds the cable from its drum. However, as soon as the hook of the drawhead becomes disengaged from the chain, the cable 84: will immediately rewind and pull the draw-head back to its starting position. In order to cushion the return movements of the draw heads, a pair of cushionin devices are provided, one for each drawead. Each of thesev devices includes a dash-pot cylinder 88 (Figs. 1b, 14 and 15) supported in a casting 89 carried by a trough 89a which connects the feed table 102 with the end stand 30. A dash-pot plunger 90 is mounted in the cylinder 88 and carries at its outer end a head 91 formed with a hook portion 92 which is beveled both towards the front and towards the rear. provided in the casting 89, this valve being constructed so as to admitair into the dashpot cylinder when the plunger 90 is pulled kout therefrom. An adjustable needlevalve 94 is also provided by which the air may be permitted to leak slowly out of the dash-pot cylinder when the plunger 90 is forced into the latter.

The head 91 of the dash-pot plunger c0- operates with a spring pressed latch member so f An air inlet valve 93 is 95 which is pivotally supported in a pair of lugs 96 which extend downwardly from the front member 50 of the draw head (Figs. 6 and 11). The latch member is provided with a nose 97 which is beveled forwardly and rearwardly to correspond with the beveled front and rear portins of the hook 92 of the head 91 of the dash-pot plunger. Secured to the frontY member 50 of the draw head, in advance of the lugs 96, is an abutment pad 98 adapted to be engaged by the flat front end of the plunger head 91. The front member 50 of the draw-head is further formed with a forwardly extending guide lug 99 which is beveled at the front and placed in such posiltion that its lower face will be engaged by the top face of the plunger head 9.1, whereby the latter is confined between the lug 99 and the nose 97 of latch member 95 (dotted lines,

Fig. 6). l 1

Prior to the starting of the drawing operation by a draw-head, i. e. when the drawhead is in the position shown in Fig. 1c, the dash-pot plunger head 91 will be disposed between the lug 99 and the latch member 95 with the hook portion 92 of the plunger impositively engaged over the nose piece 97 of the latch member 95. )When the hook 56 of the draw-head is engaged with its chain, so as to cause the draw-head tomove to the right, as seen in Fig. 1c, the draw-head, owing to the connection between the latch member 95 and the plunger head 91, will pull out the dash-pot plunger 90 until the end of the latter reaches the end of the dashpot cylinder 88 and is thereby stopped. A buffer spring 88a is provided at the end of the cylinder 8 8 for cushioning purposes.

aerofiie Upon the stoppage of the dash-pot plunger, the spring pressed latch member 95, by reason of the beveled shape of its nose 97 and of the hook 92, springs downward and releases the plunger head 91, whereupon the draw-head continues its movement leaving the dash-pot plunger in a stationary extended position. After tne hook 56 of the drawhead has become released from its chain, as above described, upon the tube leaving the die, it is returned at a considerable speed by reason of the. retracting action of its cable 84. During such return movement, the pad 98 strikes the end of the plunger head 91, the latch member springing down to permit its nose 97 to become again interlocked with the^hook 92 of the plunger head, and the plunger 90 is forced inward with respect to the dash-pot cylinder 88 and against the pressure of the air contained therein. By this means the latter part of the return movement of the draw-head is cushioned and any undesirable impact avoided.

1n operating the apparatus a tube b to be drawn is taken from the rack constituted by the rack bars 44, threaded upon a bulb rod 100, andlaid in a suitably shaped groove 101 formed in the top of the feed table 102 (Fig. 3), and its swaged-down end is passed through the die and entered between the jaws of the tongs of the draw-head. Thereupon the valve is actuated to admit pressure fluid to the cylinder 77, thus to causethe draw-head to start its drawing movement. After the drawing movement has continued long enough for the swaged-down end of the tube to have passed the die, the bulb rod is actuated so as to force the bulb into cooperative relation with the die, fluid pressure actuated bulb rod manipulating mechanisms, one for each bulb rod, being provided for this purpose. The time of forcing home the bulb will vary with different jobs, and, to allow 'for this, adjustable control means, taking the form o'f adjustably y controlled valves for the bulb manipulating mechanism, are provided. The adjustable control means are actuated from the dash pot plungers 90 which, to that end, arev provided with stems 103 which extend rearward fr r a considerable distance beneath the feed table 102.

Each stem 103 is connected at its rear end with a square rod 104 (Figs. 1a, and 19-22) which is slidably mounted in a bearing member 105 carried-by a stand 106. Mounted upon each rod 104 is a valve actuatingmember 107, the base of which is formed of two portions 108 and 109 forced towards each other by springs 110 upon studs 111, and enclosing between them friction shoes 107a which embrace the rod 104. Thus a frictional sliding connection isformed between the valve actuating lever 107 and rod 104, permitting the member 107 to move lengthwise with respect to the rod but causing it to ,valve 126 working in its housing 123, each of remain in any. position to which it may be moved. A bracket 112 is secured underneath'the feed table 102 and is provided with a bearing for a nut 113er in which is threaded a stem 11S-which extends lengthwise and centrally beneath the feed table. Upon .fthe nut 1135i is keyed a spiral pinion 114 which meshes with a second spiral pinion 115 secured to a transverse shaft 116 carried in suitable bearings in the bracket 112. A handwheel 117 is mounted on the outer end of the shaft. 116, and a cross head 118 is secured to the end of the threaded stem 113. 1t will be seen. that by turning the handwheel in one direction or the other the cross head 118 can be moved either forwardly or rearwardly with respect to the ystems 104.

The cross head 118 has secured in each end thereof a stud 119, the end of which is screwthreaded to'receive a spanner nut 120 and then reduced to enter the bore of an abutment member 121. which extends upward into the pathy of the valve actuating member 107 on one of the rods 104. The stud 119 is threaded at its end to receive a second nut 122 which clamps the abutment member in position on the st-ud. By manipulating the nuts 120 and 122, a fine adjustment of the respective positions of the two abutment members 121 may be obtained, while by operating the handwheel 117 the two abutment members can be adjusted simultaneously. I

Pivotally mounted on valve housings 123 carried by the stand 106, and one disposed in the path of each of the valve-actuating members 107, are a pair of valve levers 124. Each valve lever is provided with a roller 125 adapted to be engaged by the adjacent valveactuating member 107 and operates a suitable y which latter is connected by a pipe 127 (Fig. la) with one of the two cylinders of the bulb rod manipulating mechanism. The valve construction is such that when a valve lever 124 is in the uprightposition shown in Figs.

1a and 19, the pipe 127 is open to the atmosphere, but when such valve lever is rocked to the right on its pivot the pipe 127 is connected with a "source of fluid under pressure which has the effect of operating the bulb manipulating mechanism to canse the bulb to be forced forward into cooperative relation with the die.

During the pushing in of a dash-pot plunger 90 at the end of the ret-urn movement o a draw-head, the valve. actuating member 107 carried by the rod 104 of the plunger will move a short distance (to the left, Fig. 19) with` its rod, until the ends of .its shoes 1070 come into engagement with the end of one ofthe abutment.y members 121. Thereafter, the member 107 will remain stationary, its rod 104 sliding frictionally therein. When the dash-pot plunger begins tomove with the draw-head at the start of the drawing operation, the valve actuating member 107 moves to the right with its rod 104 until it reaches and engages the roll 125 of the associated valve lever 124 tilting such lever and admitting fluid under pressure to the pipe 127 and causing the bulb rod manipulating mechanism to be actuated. 1t will be observed that the time at which this occurs is dependent upon the distance traversed by the member 107 before it strikes the roll 125, and thus upon the place of prior stoppage of the member 107, which in turn is determined by the adjustment of the cross head 118. 1n this way the adjustment by means of the handWheel 117 is made to determine the period, after the starting of the drawing operation, at which the bulb is forced home with respect to the die, which period varies with the length of the swaged end of the tube and other conditions.

After one of the valve actuating members 107 has operated its valve lever 124, as above described, the ends of its shoes 107e strike the bearing member 105, whereby the actuating member is again stopped, its rod 104 continuing its movement to the right until such movement is completed. Upon the dash-pot plunger starting to move to the left, during the latter part of the return movement of the corresponding draw-head, the valve actuat ing member 107 upon its rod 104 moves with such rod until it strikes the abutment member 121, as above described. The first part of this return movement of the member 107 permits its valve lever 124, under the action of a spring 128, toresume an upright position,

thereby opening the pipe 127 to the atmosphere and permitting the bulb rod to be pushed back by the operator into position for receiving another tube, as will be described below.

The bulb rod manipulating mechanism (Figs. 1a, 2 and 16S-,18) includes a table 129 which forms a continuation of the feed table 1Q2 and is supported upon standards 130. A pair of bases 129e are secured to the table adjacent the left-hand end of the latter, which bases have bearing blocks 131 extendingup- Wardly therefrom at their right-hand ends. These bearing blocks have slidably mounted vtherein stems 132 equipped with abutment heads 133 at their left-hand ends. At their righthand ends, the stems have internally screw-threaded sleeves 134 secured thereto. The bulb rods 100 are threaded into the sleeves 134 and'secured therein by lock-nuts135. The proper spacing of the bulb with respect to the die, when in cooperative relation with the latter, will vary with different jobs, depending on the desired wall thickness of the drawn tube, etc. An adjustment to provide for this can be made by loosening the locknuts 135 and screwing the bulb rods into or out of the sleeves 134. Since, as will be described below, the final position of the' bulb rods is determined by the engagement of the abutment heads 133 against the ends of the bearing blocks 131, the above adjustment will determine the distance separating the dies and the bulbs in the final position of the later.

Mounted on the bases'129a and disposed in axial alignment with the stems 132, are a pair of cylinders 136 having plungers 137, of relatively large diameter, therein which are provided with abutment heads 138 similar to the abutment heads 133 of the stems 132. lVhen the plungers 137 are retracted into the cylinders 13G, the space between the heads 133 and 138 is sutiicient to enable the operator to push back the bulb rods sulficiently to be able tothread a fresh tube thereon.

The pipes 127 leading from the above-deu scribed adj ustably controlled valves 126 enter the cylinders 136 at their outer ends, and pipes 139 connected with the source of supply of pressure fluid enter the cylinders at their inner ends. After a drawing operation, and upon return of the draw-head which performed it, the valve actuating member 107 for that draw-head will move to the left, thus permitting the valve lever 124 to resume its upright position, whereby the pipe 127 is opened to the atmosphere, as described above. tering the cylinder 136 through the inlet 139 to force the plunger 137 to the left, into the position shown in Fig. 17. The operator can then push the bulb rod back until the abutment member 133 engages the abutment member 133, which provides room at the front end ofthe bulb rod for threading a fresh tube thereon preparatory to inserting it through the die into the tongs of the drawhead. After the drawing operation has been started, and by the time it has continued long enough for the swaged 'end of the tube to have passed the die, the valve lever 124 will be rocked to the right, whereby the pressure fluid is admitted to the pipe 127, as described above. By reason of the greater effective area on the left than on the right hand side of the piston,'the plunger 137 is forced toward the right, its abutment memi ber 138 pushing against the abutment member 133 and forcing the stem 132 and bulb rod towards the right until the abut. ment member 133 en ages the end of the bearing block 131 and is thereby stopped.

As has been said, the adjustment by means of the sleeve 134 has been made so that when the abutment member 133 engages the bean ing block 131, the bulb is in the proper position with relation to the die.

The operation of the apparatus is as follows: For any particular job, the requisite dies will, of course, first be installed in the y die holder 30a and the requisite bul-bs mounted upon the bulb rods 100. The adjustment will thenbe made, by means of the sleeves ICD 134 (Figs. 1a and 17) so that when the abutment members 133 are made tov engage the bearing blocks 131 the bulbs will occupy the proper position relatively to the dies, so as to give the desired thickness of tube wall. Next the adjustment by means of the hand wheel 117 is made so that the abutment members 121 for the \valve actuating members 107 (Figs.v 1a and 19) will occupy the proper position to cause thel bulb rods to be forced home into cooperative relation with the dies at the correct time in the drawing operation, this time depending on the length of the swaged down end, etc. Supposing now that a tube is in the process of being dra-wn by one draw-head and that the ot-her draw-head, having drawn a tube, has been returned to the starting position shown in Fig. 1c, the description immediately following will relate exclusively to the latter draw-head and the individual dash-pot plunger, valve ac-` tuating member, valve, and b-ulb manipulating cylinder and plunger mechanism associated with such latter draw-head.

During the returning of the draw-head to the position shown in Fig. 1c, its front member engaged against the head 91 of the dash-pot plunger, pushing the latter. into `its cylinder 88. Such engagement also resulted in the front member 50 of the draw-head stopping temporarily while the rear member 49 continued its movement, so that a relative movement occurred between theetwo drawhead members, resulting Iin the tongs being opened. The tongs were thereafter' held open by the pull of the cable 84 upon the rear member 49 opposed by the pressure of the plunger head 91 against the front member 50 of the draw head. Thus when the draw head reached the position shown in Fig. 10 the jaws of its tongs were open, readv to receive the swaged-down end of a new tube. During the latter part of the return of the draw-head, also, accompanied bythe pushing to the left of the dash-pot plunger 90 and the stem 103 and rod 104 associated therewith, the valve actuating member 107 mounted on the rod 104 has allowed the valve lever 124 to spring back into its upright position, thereby opening Athe left hand end of the cylinder 136 of the bulb manipulating mechanism to the atmosphere and allowing the pressure fluid,

entering the cylinder 136 through the inlet 139,`to move the plunger 137`to the left (Fig.

17), freeing the rear end of the bulb rod 100.

.The operator then pushes back the bulb rod until the abutment member 133 at the end of its stem 132 approaches or engages the abutment member 138 at. the end of the plunger 137, and, taking down a fresh tube from the rack constituted by the rack bars 44, threads t it upon thev bulb rod 100 and then inserts the swaged-down end through the die and into the open tongs of the draw-head. The operator thereupon actuates the valve for admitadmission of pressure fluid to the upper part of the cylinder 77 the hook actuating lever 58 is depressed, causing the hook 56 to be raised into a position where it will catch into one of the cross links of the adjacent chain 38, whereupon the draw-head starts its excursion to the right to eect the drawing operation. When the draw-head starts to move, its front member 50 is retained by reason of the engagement of its latch member 95 with the head 91 of the dash-pot plunger; s o that the rear member 49 of the draw-head first starts to move alone, causing a relative movement between the front and rear members which results in the closing of the .tongs upon the end of the tube. After the tongs have thus been closed, the front and rear members 50 and 49 of the draw head move together, drawing the tube through the die and pulling the 'daslrpot plunger 90 out from its cylinder 88. After the drawing movement has progressed far enough for the swaged-down end ofthe tube to have passed through the die, `the dash-pot plunger will have been pulled to the right far enough forthe valve actuating member 107 carried by the rod 104 associated with the stem 103 thereof to have engaged its associated valve lever 124 (Fig. 1a) and rocked the latter to the right, thus admitting pressure fluid to the pipe 127 and causing the plunger 137 of the bulb rod ma: nipulating mechanism to be forced to the right, whereby the bulb rod 100 is also pushed to the right until the abutment member 133 on its stem 132 has engaged the end of the bearing block 131, by which time the bulb will be in the proper position relatively to the die. During the further movement lof the draw-head to the right the dash-pot plunger 90 will move with it until the plurger reaches the end of its cylinder 88, whereby further movement of the dash-pot plunger to the right is prevented. `The latch member the tube to-fall outitherefrom, roll down the skids 40v and drop into the trough formed by the members 42. Upon the jerk beingl communicated to the rear member 49 of the drawhead by reason of the front member 50 reaching the. limit of its slotted connection with .the eiect of opening the tongs and allowing the rear member, the rear member is caused to move to the right relatively to the chain 38, whereby the hook 56 becomes treed from the chain-link with which it has been engaged. rlhe hook 56 being heavier than its actuating lever 58 falls down out of the path oi the chain, whereupon the cable 84C, which has been unwound from its drum during the previous movement of the draw-head, returns the draw-head rapidly to the left. rllowards the end of such return movement, the pad 98 on the front member of the draw-head strikes the head 91 of the dash-pot plunger, and the further return movement of the draw head causes the dash-pot plunger to be pushed into its cylinder, whereby the iinal part ot the return movement of the draw-head is properly cushioned.

t will` be seen that the construction einploying endless chains as driving members for the draw-heads, thus avoiding delay for the return of any draw-head-actuating device, coupled with the suspension of the drawlieads, permitting the drawn tubes to tall down and thus avoiding any delay tor the removal of the tubes, gives the apparatus a special rapidity of action, enabling another drawing operation to be started almost immediately one is completed. This quickness of operation is further assisted by the rcwinding cable construction, which, with the cushioning devices, provides for an exceptionally quick return of the draw-heads, and by the automatic release, of the drawn tubeV and the automatic disconnection of the drawhead from its chain instantaneously upon each drawing operation being completed.` The production speed of the apparatus is turther increased by the automatic driving home of the bulb at the right instant after the start of the drawing operation.

lit will bev noted, further, that the Yapparatus requires but one operator, whose sole duties are to take the tubes from the supplyA rack, where they are very conveniently disposed for that purpose, thread them onto the bulb rods, insert their ends through the dies into the tongs of the draw-heads, and operate the valves for starting the draw-heads. The automatic features ofthe apparatus, combined with the construction employing two draw-heads in association with the supply rack, permit an advantageous continuity of operation, the operator being enabled to ,take "lown a fresh tube, thread it onto the bulb rod, and insert its end through a die', while the preceding tube is being drawn.,

Further advantages of the apparatus are the simplity of its construction, the relatively small amount ofcfloor space which it occupies, and its accessibility both for filling the supply rack and for removing the drawn tubes.

The invention having been thus fully de- Lec/e419 scribed, what is claimed, and desired to be secured by Letters Patent, is:

l. An apparatus for drawing tube by means ot a die and bulb, comprising a draw-head, means tor advancing and returning said draw-liead, a movable member for cushioning the return movement of said draw-head, mechanism for manipulating the bulb to move it into cooperative relation with the die, and means associated with said movable member for controlling the operation of said manipulating mechanism.

2. An i apparatus for drawing tube by means of a die and bulb, comprising a drawhead, a. plunger disposed in the path of said draw-head for cushioning the return nievement of the latter, means for connecting said plunger with said draw-head during part of the forward movement ofthe latter, mechanism for manipulating the bulb to move it into cooperative relation with the die, and means associated with said plunger for controlling the operation of said manipulating mechanism.

3. An apparatus for drawing tube by means of a die and bulb, comprising a drawhead, a plunger disposed in the path of said draw-head for cushioning the return movement of the latter, means for connecting said plunger with said draw-head during part of 'the forward movement of the latter, mechanism for manipulating the bulb to move it int-o cooperativerelation with the die, and a member slidably associated with said plunger forcontrolling the operation' of said manipulating mechanism.

,4. An apparatus for drawing tube by means of a die and bulb, comprising a drawhead, a plunger disposed in the path of said draw-head for cushioning the return movement of the latter, means for connecting said plunger with said draw-head during part of the for verd movement of the latter, Vmechanism for manipulating the bulb to move it into cooperative relation with the die, a member slidably associated with said plunger for controlling the operation of said maiiipulating mechanism, and adjustable means for limiting thesliding movement of said niember in the direction of return of said drawhead, whereby the operation of said manipulating mechanism can be adjusted to ,accord with the desired position ot said draw-head.

An apparatus for drawing tube by means of a die and bulb, comprising a drawhead, means for advancing and returning said draw-head, a plunger disposed in the patn of said draw-head for cushioning the return movement of the latter, means for connecting said plunger with said draw-head during part of the advancing movement of the latter, a fluid controlled plunger for manipulating the bulb to move it into cooperative relation with the die, a valve device for controlling the supply of fluid to said lll,

I second-named plunger, a member slidably associated with said first-named plunger for actuating said valve, and adjustable means for limiting the sliding movement of said member in the direction of return of said draw-head.

.6. A drawing apparatus comprising a y guide rail, a carriagearranged to reciprocate carriage, whereby upon release of the article by said grasping means the article falls out ci' the path of the carriage to permit return of the latter by said retracting means.

. 7. A drawing apparatus comprising a guide rail, a carriage arranged to move on said rail beneath the latter, an endless driving member extending longitudinally of the guide rail and disposed with its lower reach above said carriage, releasable means mountv ed on said carriage to couple the latter with the lower reach of said driving member, releasable means carried by said carriage for grasping the article to be drawn, and impositively actuated means connected to said carriage and continuously tending to retract the same, whereby upon release of said coupling means andi said graspingy means the article falls out of the path of said carriage and the latter is automatically retracted.

8. A drawing apparatus comprising a guide rail, a carriage arranged to move on said rail beneath the latter, an endless driving member extending longitudinally of said guide member and disposed with its lower reach above said carriage, means for coupling said carriage to the lower reach of said driving member, means on said carriage for grasping the article to be drawn, said coupling means and grasping means being constructed ttor automatic release upon the occurrence of the jerk occasioned by the drawn article leaving the die, and means for auto! matically returning said carriage, whereby upon the completion of the drawing operation the drawn article falls out of the path oit said carriage and permits returnor" the latter by said automatic returning means.

9. A drawing apparatus comprising a guide rail, a carriage arranged to move on said railbeneath the latter, an endless drivin member extending longitudinally of said guide rail and disposed with its lower' reach above the latter, means for coupling said carriage with'the lower reach of said driv ing member, means on said carriage for grasping ythe article to be drawn, said coupling grasping means being construct/adder automatic release upon the occurrence of the jerk occasioned by the drawn article leaving the die, and impositively actuated means connected with said carriage and continuously tending to retract the same, whereby upon completion .of the drawing operation the art-iclefalls out of the path'or said carriage and the latter is automatically re-I tracted. y

10. ln tube drawing apparatus, the combination with a die and bulb movable into and out or' cooperative relation with the die, of a draw-head movable to eect the drawing operation, a member associated with said drawhead to participate in the movement thereof, mechanism for manipulating the bulb to move it into cooperative relation with the die,

a member adapted at a predetermined position to actuate said mechanism, said member being connected with said first-named member so as to move therewith unless prevented, and adjustablel means for stopping the movement of said second-named member with said first-named member, thereby to vary the position ot said second-named member with rel spect to said first-named member and control the stage of the movement of said first-named member at .which said manipulating mechanism is actuated.

11. In tube drawing apparatus, the combination with a die and a bulb movable into and out of cooperative relation with the die, of a draw-head movable to effect the drawing operation, a :fluid operated plunger for manipusie lating the bulb to move it into cooperative .y

relation with the die, a valvey for controlling the supply of iiuid for said plunger, a-,member associated with said draw-head to participate in the movement thereof, a member adapted at a predetermined position to actuate said valve, said member being connected with said Erst-named member so as to move therewith unless prevented, and adjustable means for stopping the movement of said second-named member with said first-named member, thereby to vary the position of said second-named member with respect to said first-named member and to control the stage of movement of said rst-named member at which said valve is operated.

l2. ln a drawing apparatus, a draw-head comprising a front member slidably connected to a rear member, material grasping tongs associated with said draw-head so that relative movement of said liront and rear members eects the opening and closing of said tongs, a driving member for said drawhead, means for connecting said draw-head to said driving member to advance the same,

means for automatically returning said draw-head independently oi said driving member, and means for cushioning the return movement of said draw-head, said cushioning means comprising a dash-pot cylinder and pler, the plunger being disposed in 311' the palt-h of the draw-head, latch means associated with said front member of the drawhead for 'impositively connecting the plunger to said 'front member during part of the 5 advance movement of the draw-head to produce 4aJ drag on the front member to close the graspin tongs and to draw a supply of cushloning uid intosaid dash-pot cylinder.

In testimony whereof, we hereunto sign 10 our names.

ROY D. PALMER; ROLAND L. yJEFFERS. 

